v1.2.0: Support packages.config and exclude the attributes from code coverage by default

[manuelroemer]

v1.2.0

This release provides solutions for issue #1 and
issue #6. In addition, potential compiler
warnings in the NullableAttributes.cs file are now hidden.

Upgrading:

Remove any previously defined NULLABLE_ATTRIBUTES_EXCLUDE_FROM_CODE_COVERAGE compiler constant,
as it does not have any effect anymore.

ℹ️ Note:

Builds will NOT break if the constant is still defined. It is simply ignored now.

Details:

• The package now supports packages.config via a content/ folder in the NuGet package.
• The attributes are now excluded from code coverage by default.
  When referenced from projects targeting .NET Standard >= 2.0 or .NET Framework >= 4.0, the
  ExcludeFromCodeCoverageAttribute is used. For other project types, the DebuggerNonUserCodeAttribute
  is used.
• Added support for the NULLABLE_ATTRIBUTES_INCLUDE_IN_CODE_COVERAGE compiler constant which
  removes the code coverage attributes.
• The NULLABLE_ATTRIBUTES_EXCLUDE_FROM_CODE_COVERAGE compiler constant no longer has
  any effects. Code coverage is now disabled by default.
• The NullableAttributes.cs file now wraps the attributes with a #pragma warning disable and
  #pragma warning restore block to disable both compiler- and code-analysis warnings.